Doesn't recover gracefully from failures

[peterflynn]

I ran into a problem like this today:

1. Run grabem to get the full set of extensions (a week or so ago)
2. Run grabem again to get updates
3. Error deleting the folders from extensions that existed before but now have updates. (For whatever reason*)
4. Close some apps and run grabem again

Result:
The last grabem invocation only picks up further updates that occurred between step 2 and 4. It doesn't update the extensions that failed to update at step 2. The folders for those extensions are left completely empty.

* I'm not sure if this happens 100% of the time, at least on my Win machine, or if something was going on that was holding onto file handles in these folders and preventing deletion... although since the folders wound up completely empty it suggests there was no one holding onto any specific file in there. It's still possible some app had a handle on the folder itself, but that seems pretty uncommon.

[peterflynn]

Workaround: delete everything in the 'downloads' folder except for 'downloads/zip' -- then I think grabem will recreate all the unzipped folders cleanly, but without redownloading all the ZIPs from the server.

[dangoor]

Thanks for the report, Peter. I'm not super likely to touch this script again very soon (or on Windows, for that matter), but I'll keep this in mind if I do have a need to hack on it again sometime soon...